Display apparatus having dummy contact holes

ABSTRACT

A display apparatus including a substrate including a display area and a peripheral area outside the display area, a first insulating layer over the substrate in the display area and the peripheral area, the first insulating layer including a plurality of first contact holes located in the display area, a plurality of second contact holes located in the peripheral area, and a plurality of dummy contact holes located between the plurality of first contact holes and the plurality of second contact holes, first wirings filling the plurality of first contact holes, second wirings filling the plurality of second contact holes, and a second insulating layer covering the first wirings and the second wirings and filling the plurality of dummy contact holes.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This is a continuation application of U.S. patent application Ser. No.16/123,270 filed Sep. 6, 2018 (now U.S. Pat. No. 10,978,519), thedisclosure of which is incorporated herein by reference in its entirety.U.S. patent application Ser. No. 16/123,270 claims priority benefit ofKorean Patent Application 10-2017-0176487 filed Dec. 20, 2017, in theKorean Intellectual Property Office, the disclosure of which isincorporated herein by reference in its entirety for all purposes.

BACKGROUND 1. Field

One or more embodiments relate to a display apparatus.

2. Description of the Related Art

In general, a display apparatus has a display area, and many pixels arelocated in the display area.

SUMMARY

Embodiments are directed to a display apparatus including a substrateincluding a display area and a peripheral area outside the display area,a first insulating layer over the substrate in the display area and theperipheral area, the first insulating layer including a plurality offirst contact holes located in the display area, a plurality of secondcontact holes located in the peripheral area, and a plurality of dummycontact holes located between the plurality of first contact holes andthe plurality of second contact holes, first wirings filling theplurality of first contact holes, second wirings filling the pluralityof second contact holes, and a second insulating layer covering thefirst wirings and the second wirings and filling the plurality of dummycontact holes.

Each of the first wirings may be electrically connected to acorresponding one of the second wirings.

Each of the first wirings may be integrally formed with a correspondingone of the second wirings.

Each of the first wirings may include a same material as a correspondingone of the second wirings.

The first wirings may be electrically connected to conductive layers.The second wirings may be electrically connected to the conductivelayers.

The display apparatus may further include a plurality of firstsemiconductor layers between the substrate and the first insulatinglayer. At least a part of an upper surface of each of the plurality offirst semiconductor layers that faces the first insulating layer, islocated at a lower end the plurality of first contact holes, and aplurality of second semiconductor layers between the substrate and thefirst insulating layer, wherein at least a part of an upper surface ofeach of the plurality of second semiconductor layers that faces thefirst insulating layer is located at a lower end of the plurality ofsecond contact holes.

The display apparatus may further include a plurality of dummysemiconductor layers between the substrate and the first insulatinglayer. At least a part of an upper surface of each of the plurality ofdummy semiconductor layers that faces the first insulating layer islocated at a lower end of the plurality of dummy contact holes.

At least a portion of an edge of the display area may have a roundshape. The plurality of dummy contact holes may be located adjacent tothe portion of the display area having the round shape.

An edge of the display area may include a first portion and a secondportion. Some contact holes of the plurality of first contact holes andsome contact holes of the plurality of second contact holes may belocated adjacent to the first portion. Other contact holes of theplurality of first contact holes and other contact holes of theplurality of second contact holes may be located adjacent to the secondportion. The plurality of dummy contact holes may be located adjacent tothe second portion.

A shortest distance between the some contact holes of the plurality offirst contact holes and the some contact holes of the plurality ofsecond contact holes may be less than a shortest distance between theother contact holes of the plurality of first contact holes and theother contact holes of the plurality of second contact holes.

The second portion may have a curved shape.

The display apparatus may further include a conductive material layerlocated in the plurality of dummy contact holes. An end portion of theconductive material layer facing the second insulating layer may belocated in the plurality of dummy contact holes.

A surface of the first wiring facing the substrate may directly contacta surface of the first insulating layer facing away from the substrate.

The display apparatus may further include connecting wires thatelectrically connect each of the first wirings to corresponding ones ofthe second wirings. An edge of the display area may include a firstportion and a second portion. Some contact holes of the plurality offirst contact holes and some contact holes of the plurality of secondcontact holes may be located adjacent to the first portion. Othercontact holes of the plurality of first contact holes and other contactholes of the plurality of second contact holes may be located adjacentto the second portion. The plurality of dummy contact holes may belocated adjacent to the second portion. The connecting wires may includefirst connecting wires passing between the plurality of dummy contactholes and second connecting wires other than the first connecting wires.A largest distance between closest ones of the first connecting wiresmay be greater than a largest distance between closest ones of thesecond connecting wires.

Embodiments are also directed to a display apparatus including asubstrate including a display area and a peripheral area outside thedisplay area, a first insulating layer over the substrate in the displayarea and the peripheral area, the first insulating layer including aplurality of first contact holes located in the display area, aplurality of second contact holes located in the peripheral area, and aplurality of dummy contact holes located between the plurality of firstcontact holes and the plurality of second contact holes, and connectingwires electrically connecting a material filling each of the pluralityof first contact holes and a material filling a corresponding one of theplurality of second contact holes, and passing between the plurality ofdummy contact holes.

BRIEF DESCRIPTION OF THE DRAWINGS

Features will become apparent to those of skill in the art by describingin detail exemplary embodiments with reference to the attached drawingsin which:

FIG. 1 illustrates a conceptual diagram schematically depicting adisplay apparatus in a manufacturing process according to an embodiment;

FIG. 2 illustrates a conceptual diagram schematically depicting aportion A of FIG. 1 ;

FIG. 3 illustrates a conceptual diagram schematically depictingpositions of contact holes in FIG. 2 ;

FIG. 4 illustrates a cross-sectional view schematically depicting aportion of the display apparatus of FIG. 1 ;

FIGS. 5 and 6 illustrate conceptual diagrams showing the generation ofdefects in a manufacturing process according to the density of positionswhere contact holes are to be formed; and

FIG. 7 illustrates a cross-sectional view schematically depicting aportion of a display apparatus according to another embodiment.

DETAILED DESCRIPTION

Example embodiments will now be described more fully hereinafter withreference to the accompanying drawings; however, they may be embodied indifferent forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey exemplary implementations to those skilled in the art.

In the drawing figures, the dimensions of layers and regions may beexaggerated for clarity of illustration. It will also be understood thatwhen a layer or element is referred to as being “on” another layer orsubstrate, it can be directly on the other layer or substrate, orintervening layers may also be present. Further, it will be understoodthat when a layer is referred to as being “under” another layer, it canbe directly under, and one or more intervening layers may also bepresent. In addition, it will also be understood that when a layer isreferred to as being “between” two layers, it can be the only layerbetween the two layers, or one or more intervening layers may also bepresent. Like reference numerals refer to like elements throughout.

FIG. 1 is a conceptual diagram schematically illustrating a displayapparatus in a manufacturing process according to an embodiment. FIG. 2is a conceptual diagram schematically illustrating a portion A of FIG. 1.

The display apparatus according to the embodiment illustrated in FIG. 1may include a display area DA where a plurality of pixels are locatedand a peripheral area PA disposed outside the display area DA. Asubstrate 100 (see FIG. 4 ) may be understood to have the display areaDA and the peripheral area PA. Various electronic components or printedcircuit substrates may be electrically attached to the peripheral areaPA. Also, various electronic components may be directly formed in theperipheral area PA of the substrate 100.

The substrate 100 may include a suitable material such as, for example,glass or metal. In some implementations, the substrate 100 may includevarious materials having flexible or bendable characteristics, forexample, a polymer resin such as polyethersulfone (PES), polyacrylate,polyetherimide (PEI), polyethylene naphthalate (PEN), polyethyleneterephthalate (PET), polyphenylene sulfide (PPS), polyallylate (PAR),polyimide (PI), polycarbonate (PC), or cellulose acetate propionate(CAP). The substrate 100 may be modified in various ways. For example,the substrate 100 may have a multilayer structure of two layers, eachlayer including polymer resin, and a barrier layer disposed between thelayers and including an inorganic material such as silicon oxide,silicon nitride, or silicon oxynitride.

The edge of the display area DA may have an overall shape similar as awhole to a rectangle or a square. However, as illustrated in FIGS. 1 and2 , the display area DA may include a rounded shape at a portion A at acorner edge. In detail, the display area DA may include a first edge E1and a second edge E2 facing each other and a third edge E3 and a fourthedge E4 facing each other and located between the first edge E1 and thesecond edge E2. A pad area may be adjacent to the fourth edge E4. Theportion A having a round shape may connect the first edge E1 and thethird edge E3. The display area DA may also have a round shape in aportion of the edge other than the portion A. For example, a portionconnecting the second edge E2 and the third edge E3 may have a roundshape. The display area DA may have a round shape in other portions ofthe edge.

As illustrated in FIGS. 1 and 2 , in a normal use environment in which auser uses the display apparatus according to the present embodiment oran electronic apparatus including the display apparatus, the portion Aof the edge is recognized to have a round shape, that is, a curvedshape. However, when the portion A is magnified enough to view wireshaving a width of several micrometers or tens of micrometers, theportion A may appear to have a linear shape bent a plurality of times.Although the portion A, when observed by being magnified, appears tohave the linear shape bent a plurality of times, in the normal useenvironment, the portion A is recognized to have a round shape, that is,a curved shape. Accordingly, in the following description, the portion Ais described as having a round shape.

A plurality of pixels are located in the display area DA along theportion A having the round shape. For convenience of illustration, FIG.2 does not illustrate pixels. Various signals may be applied to thepixels in the display area DA. For example, in order to apply a datasignal for controlling brightness to pixels located in a rowhorizontally extending in FIG. 2 , a scan signal may be applied to thepixels in the row to select the pixels of the row. To this end, variouswires such as scan lines that are illustrated to horizontally extend inFIG. 2 may be located inside and outside the display area DA. FIG. 2illustrates scan lines SL1, SL2, and SL3. The scan lines SL1, SL2, andSL3, as described below, may include the same material as a sourceelectrode 215 a or a drain electrode 215 b of a thin film transistor 210(see FIG. 4 ) and may be located in the same layer, may include the samematerial as a gate electrode 213 (see FIG. 4 ) and may be located in thesame layer, or may be located in a separate layer.

A drive circuit may be located in the peripheral area PA, as illustratedin FIG. 2 . FIG. 2 illustrates that a first scan drive circuit SDR1, asecond scan drive circuit SDR2, and a third scan drive circuit SDR3 arelocated in the peripheral area PA outside the display area DA. The firstscan drive circuit SDR1 to the third scan drive circuit SDR3 maygenerate scan signals to be applied to pixels in the display area DA viathe scan lines SL1, SL2, and SL3. Accordingly, the scan lines SL1 may beelectrically connected to the first scan drive circuit SDR1, the scanlines SL2 may be electrically connected to the second scan drive circuitSDR2, and the scan lines SL3 may be electrically connected to the thirdscan drive circuit SDR3. In some implementations, the first scan drivecircuit SDR1 to the third scan drive circuit SDR3 may not be separatedfrom one another, but instead may be a single scan drive circuit.

For reference, the functions of the first scan drive circuit SDR1 to thethird scan drive circuit SDR3 may be implemented by a thin filmtransistor and/or a capacitor formed on the substrate, and not byelectronic components attached on the substrate 100. For example, thinfilm transistors and/or capacitors may be formed to control emission ora degree of emission of the pixels in the display area DA. When the thinfilm transistors and/or capacitors are formed in the display area DA,thin film transistors and/or capacitors may be simultaneously formed ofthe same material in the peripheral area PA, thereby forming the firstscan drive circuit SDR1 to the third scan drive circuit SDR3.

The first scan drive circuit SDR1 to the third scan drive circuit SDR3and the scan lines SL1, SL2, and SL3 may be electrically connected toeach other. To this end, connecting wires CW1 and CW2 may be providedbetween the first scan drive circuit SDR1 to the third scan drivecircuit SDR3 and the scan lines SL1, SL2, and SL3. The connecting wiresCW1 and CW2 may include the same material as the source electrode 215 aor the drain electrode 215 b of the thin film transistor 210, which isdescribed below, and may be located in the same layer or in anotherseparate layer. The connecting wires CW1 and CW2 may be located in adifferent layer from the scan lines SL1, SL2, and SL3. The connectingwires CW1 and CW2 may be connected to the scan lines SL1, SL2, and SL3via a contact hole formed in an insulating layer between the connectingwires CW1 and CW2 and the scan lines SL1, SL2, and SL3. In someimplementations, the connecting wires CW1 and CW2 and the scan linesSL1, SL2, and SL3 may be simultaneously formed of the same material inthe same layer. In this case, bridge wires electrically connecting theconnecting wires CW1 and CW2 and the scan lines SL1, SL2, and SL3 may belocated in a different layer from the connecting wires CW1 and CW2 andthe scan lines SL1, SL2, and SL3. Each of the connecting wires CW1 andCW2 and any one of the scan lines SL1, SL2, and SL3 correspondingthereto may be formed in one body.

As illustrated in FIGS. 1 and 2 , in a first portion EP1 that is a partof the first edge E1 that is a linear edge of the edges of the displayarea DA, a gap between the third scan drive circuit SDR3 locatedadjacent to the first portion EP1 and the first portion EP1 may besmall. In particular, in order to reduce a dead space in the displayapparatus by increasing a ratio of the display area DA in the entiresurface of the substrate 100, the gap between the third scan drivecircuit SDR3 and the first portion EP1 may be minimized.

However, as illustrated in FIG. 2 , in a second portion EP2 that is acurved edge of the display area DA, a gap between the first scan drivecircuit SDR1 or the second scan drive circuit SDR2, which are locatedadjacent to the second portion EP2, and the second portion EP2 may berelatively large. For example, the gap between the first scan drivecircuit SDR1 or the second scan drive circuit SDR2, which are locatedadjacent to the second portion EP2, and the second portion EP2 isgreater than the gap between the third scan drive circuit SDR3 and thefirst portion EP1 due to the curved shape of the second portion EP2.Thus, extension directions of the connecting wire CW2 connecting thefirst scan drive circuit SDR1 and the scan lines SL1 and the connectingwire CW2 connecting the second scan drive circuit SDR2 and the scanlines SL2 are not uniform, Accordingly, the length of the connectingwire CW2 is increased.

FIG. 3 illustrates a conceptual diagram schematically depictingpositions of contact holes in FIG. 2 . As illustrated in FIG. 4 , thinfilm transistors are located in the pixels in the display area DA. Ineach of the thin film transistors, a first semiconductor layer (211, seeFIG. 4 ) is located under a first insulating layer 141 and a sourceelectrode (215 a, see FIG. 4 ) and a drain electrode (215 b, see FIG. 4) are located over the first insulating layer 141. The source electrode215 a and the drain electrode 215 b contact the first semiconductorlayer 211 thereunder via contact holes formed in the first insulatinglayer 141 provided between the first semiconductor layer 211 and thesource and drain electrodes 215 a and 215 b. Accordingly, a plurality offirst contact holes CT1 are located in the first insulating layer 141 inthe display area DA as illustrated in FIG. 3 . The first contact holesCT1 are located in the first insulating layer 141 in the display area DAat an approximately uniform density.

Among the first contact holes CT1, some contact holes CT11 are locatedadjacent to the first portion EP1 that is a part of the first edge E1that is a linear edge of the edges of the display area DA. Other contactholes CT12 of the first contact holes CT1 are located adjacent to thesecond portion EP2 that is a curved edge of the edges of the displayarea DA.

Thin film transistors are located in the areas of the first scan drivecircuit SDR1 to the third scan drive circuit SDR3. In each of the thinfilm transistors, a second semiconductor layer (221, see FIG. 4 ) islocated under the first insulating layer 141 and a source electrode (225a, see FIG. 4 ) and a drain electrode (225 b, see FIG. 4 ) are locatedabove the first insulating layer 141. The source electrode 225 a and thedrain electrode 225 b may contact the second semiconductor layer 221thereunder via contact holes formed in the first insulating layer 141provided between the second semiconductor layer 221 and the source anddrain electrodes 225 a and 225 b. Accordingly, a plurality of secondcontact holes CT2 are located in the first insulating layer 141 of thedisplay area DA as illustrated in FIG. 3 . The second contact holes CT2are located in the first insulating layer 141 in the first scan drivecircuit SDR1 to the third scan drive circuit SDR3, in an approximatelyuniform density.

Among the second contact holes CT2, some contact holes CT21 are locatedadjacent to the first portion EP1 that is a part of the first edge E1that is a linear edge of the edges of the display area DA. Other contactholes CT22 of the second contact holes CT2 are located adjacent to thesecond portion EP2 that is a curved edge of the edges of the displayarea DA.

As described above, in the first portion EP1 that is a part of the firstedge E1 that is a linear edge of the edges of the display area DA, thegap between the third scan drive circuit SDR3 located adjacent to thefirst portion EP1 and the first portion EP1 is relatively small. In thesecond portion EP2 that is a curved edge of the edges of the displayarea DA, the gap between the first scan drive circuit SDR1 or the secondscan drive circuit SDR2, which is located adjacent to the second portionEP2, and the second portion EP2 is relatively large. For example, thegap between the first scan drive circuit SDR1 or the second scan drivecircuit SDR2 located adjacent to the second portion EP2 and the secondportion EP2 is greater than the gap between the third scan drive circuitSDR3 and the first portion EP1. Accordingly, the shortest distancebetween the some contact holes CT11 of the first contact holes CT1 andthe some contact holes CT21 of the second contact holes CT2 is less thanthe shortest distance between the other contact holes CT12 of the firstcontact holes CT1 and the other contact holes CT22 of the second contactholes CT2.

In the display apparatus according to the present embodiment, the firstinsulating layer 141 may include a plurality of dummy contact holes DCT.The dummy contact holes DCT may be located between the first contactholes CT1 in the display area DA and the second contact holes CT2 in theperipheral area PA. The dummy contact holes DCT may also be located inthe peripheral area PA. The dummy contact holes DCT may be locatedadjacent to the second portion EP2 that is a curved edge of the edges ofthe display area DA, for example, the second portion EP2 having a roundshape of the edges of the display area DA. Accordingly, the density ofthe contact holes CT1, CT2, and DCT may be approximately uniform withouta big change in the area between the first scan drive circuit SDR1 tothe third scan drive circuit SDR3 and the display area DA, in thedisplay area DA, and in the first scan drive circuit SDR1 to the thirdscan drive circuit SDR3.

FIG. 4 illustrates a cross-sectional view schematically depicting aportion of the display apparatus of FIG. 1 . FIG. 4 is not across-sectional view taken along a line in FIG. 3 , but may beunderstood as a cross-sectional view taken along a line passing throughthe second contact holes CT2 of a thin film transistor 220 of the firstscan drive circuit SDR1 in the peripheral area PA, the dummy contactholes DCT in the peripheral area PA, and the first contact holes CT1 ofthe thin film transistor 210 in the display area DA.

As illustrated in FIG. 4 , not only a display device 310, but also thethin film transistor 210 to which the display device 310 is electricallyconnected may be located in the display area DA of the substrate 100.FIG. 4 illustrates that an organic light-emitting device as the displaydevice 310 is located in the display area DA. The electrical connectionof the organic light-emitting device to the thin film transistor 210 maybe by way of a pixel electrode 311 electrically connected to the thinfilm transistor 210.

The thin film transistor 210 may include a first semiconductor layer 211including amorphous silicon, polycrystalline silicon, or an organicsemiconductor material, the gate electrode 213, the source electrode 215a, and the drain electrode 215 b. To secure insulation from the firstsemiconductor layer 211 and the gate electrode 213, a gate insulatinglayer 121 including an inorganic material such as silicon oxide, siliconnitride, and/or silicon oxynitride may be provided between the firstsemiconductor layer 211 and the gate electrode 213. In addition, aninterlayer insulating layer 131 including an inorganic material such assilicon oxide, silicon nitride, and/or silicon oxynitride may beprovided over the gate electrode 213. The source electrode 215 a and thedrain electrode 215 b may be provided on the interlayer insulating layer131. The gate insulating layer 121 and the interlayer insulating layer131 altogether may be collectively referred to as the first insulatinglayer 141 provided between the source electrode 215 a and the drainelectrode 215 b and the first semiconductor layer 211, as describedabove. The first insulating layer 141 includes the first contact holesCT1, and thus the source electrode 215 a and the drain electrode 215 bmay contact the first semiconductor layer 211.

As such, an insulating layer 141 including an inorganic material may beformed by chemical vapor deposition (CVD) or atomic layer deposition(ALD). This will be applied to the below-described embodiments andmodified examples thereof.

The gate electrode 213 may include a metal such as molybdenum oraluminum, and may have a single layer or multilayer structure. Thesource electrode 215 a and the drain electrode 215 b may include a metalsuch as titanium or aluminum, and may have a single layer or multilayerstructure. For example the gate electrode 213 may have a tri-layerstructure of molybdenum/aluminum/molybdenum, and the source electrode215 a and the drain electrode 215 b may have a tri-layer structure oftitanium/aluminum/titanium. The same structures and compositions may beapplied to the thin film transistor 220 that is described below.

A buffer layer 110 including an inorganic material such as siliconoxide, silicon nitride, and/or silicon oxynitride may be providedbetween the thin film transistor 210 and the substrate 100, which areconfigured as above. The buffer layer 110 may improve the smoothness ofan upper surface of the substrate 100 and may prevent or reduceintrusion of foreign materials from the substrate 100 into the firstsemiconductor layer 211 of the thin film transistor 210.

A planarization layer 140 may be provided on the thin film transistor210. For example, when an organic light-emitting device is provided overthe thin film transistor 210, as illustrated in FIG. 4 , theplanarization layer 140 may substantially planarize an upper portion ofa layer under the planarization layer 140. For example, theplanarization layer 140 may substantially planarize an upper portion ofa protection film covering the thin film transistor 210. Theplanarization layer 140 may be formed of an organic material, forexample, acryl, benzocyclobutene (BCB), or hexamethyldisiloxane (HMDSO).Although FIG. 4 illustrates the planarization layer 140 as a singlelayer, in some implementations, the planarization layer 140 may be amultilayer and various modifications thereof are possible.

The display device 310 may be located on the planarization layer 140 inthe display area DA of the substrate 100. The display device 310 may bean organic light-emitting device that includes, for example, the pixelelectrode 311, a counter electrode 315, and an intermediate layer 313provided between the pixel electrode 311 and the counter electrode 315and including an emission layer. The pixel electrode 311 may beelectrically connected to the thin film transistor 210 by contacting anyone of the source electrode 215 a and the drain electrode 215 b via anopening portion formed the planarization layer 140, as illustrated inFIG. 4 .

A pixel defining layer 150 may be provided over the planarization layer140. The pixel defining layer 150 may define a pixel by having anopening corresponding to each of subpixels, for example, an opening thatexposes at least a center portion of the pixel electrode 311. Asillustrated in FIG. 4 , the pixel defining layer 150 may increase adistance between an edge of the pixel electrode 311 and the counterelectrode 315 above the pixel electrode 311, thereby preventinggeneration of arc at the edge of the pixel electrode 311. The pixeldefining layer 150 may be formed of, for example, an organic materialsuch as polyimide or HMDSO.

The intermediate layer 313 of the organic light-emitting device may havevarious structures. For example, the intermediate layer 313 may includea low molecular substance or a polymer substance. When the intermediatelayer 313 includes a low molecular substance, the intermediate layer 313may have a structure in which a hole injection layer (HIL), a holetransport layer (HTL), an emission layer (EML), an electron transportlayer (ETL), and an electron injection layer (EIL) are stacked, and maybe formed in a vacuum deposition method. When the intermediate layer 313includes a polymer substance, the intermediate layer 313 may have astructure including a HTL and an EML where the HTL includespoly(3,4-ethylenedioxythiophene (PEDOT), and the emission layer includesa poly-phenylenevinylene (PPV) based polymer substance and apolyfluorene based polymer substance. The intermediate layer 313 may beformed by a screen printing method, an inkjet printing method, or alaser induced thermal imaging (LITI) method. The intermediate layer 313may include a layer integrating the pixel electrodes 311 or may includea layer patterned to correspond to each of the pixel electrodes 311.

The counter electrode 315 may be provided above the display area DA tocover the display area DA. For example, the counter electrode 315 may beformed as one body with respect to a plurality of organic light-emittingdevices and corresponding to the pixel electrodes 311.

The buffer layer 110, the gate insulating layer 121, the interlayerinsulating layer 131, and/or the planarization layer 140 may be providedin the peripheral area PA, as illustrated in FIG. 4 . The buffer layer110, the gate insulating layer 121, the interlayer insulating layer 131,and/or the planarization layer 140 may be discontinuously arranged inthe peripheral area PA. For example, the buffer layer 110, the gateinsulating layer 121, the interlayer insulating layer 131, and/or theplanarization layer 140 in the display area DA may extend to theperipheral area PA, and may be partially removed in the peripheral areaPA. Accordingly, the buffer layer 110, the gate insulating layer 121,the interlayer insulating layer 131, and/or the planarization layer 140in the display area DA may be spaced apart from the buffer layer 110,the gate insulating layer 121, the interlayer insulating layer 131,and/or the planarization layer 140 located at the edge of the substrate100 in the peripheral area PA.

As described above, the thin film transistor 220 may be located in thefirst scan drive circuit SDR1 to the third scan drive circuit SDR3 inthe peripheral area PA of the substrate 100. The thin film transistor220 may include a second semiconductor layer 221 including amorphoussilicon, polycrystalline silicon, or an organic semiconductor material,a gate electrode 223, a source electrode 225 a, and a drain electrode225 b. The gate insulating layer 121, as described above, may beprovided between the second semiconductor layer 221 and the gateelectrode 223. In addition, the interlayer insulating layer 131 may beprovided over the gate electrode 223, and the source electrode 225 a andthe drain electrode 225 b may be provided over the interlayer insulatinglayer 131. The gate insulating layer 121 and the interlayer insulatinglayer 131 altogether may be referred to as the first insulating layer141 provided between the source electrode 225 a and the drain electrode225 b, and the second semiconductor layer 221, as described above. Thefirst insulating layer 141 may include the second contact holes CT2,through which the source electrode 225 a and the drain electrode 225 bcontact the second semiconductor layer 221.

The dummy contact holes DCT as described above may be located in aportion between the first scan drive circuit SDR1 to the third scandrive circuit SDR3 and the display area DA, which portion may be a partof the peripheral area PA of the substrate 100. The gate insulatinglayer 121 and the interlayer insulating layer 131 altogether may bereferred to as the first insulating layer 141 as described above. Thefirst insulating layer 141 may include the dummy contact holes DCT.

FIGS. 5 and 6 illustrate conceptual diagrams showing the generation ofdefects in a manufacturing process according to the density of positionswhere contact holes are to be formed. Referring to FIG. 5 , ato-be-patterned layer 2 is located on a base layer 1, and a photoresistlayer 3 is located on the to-be-patterned layer 2, to pattern theto-be-patterned layer 2. In the photoresist layer 3, a portion 3 a is apart of the photoresist layer 3 that is not removed and remains, andportions 3 b and 3 c are parts of the photoresist layer 3 that are to beremoved.

In a development process to remove the portions 3 b and 3 c from thephotoresist layer 3, a developer contacts the entire surface of thephotoresist layer 3. In this state, since the portion 3 a of thephotoresist layer 3 is not a part to be removed, the developer hardlyreacts to the portion 3 a of the photoresist layer 3, and accordinglythe developer on the portion 3 a of the photoresist layer 3 mainlyreacts to the portions 3 b and 3 c of the photoresist layer 3therearound, which are to be removed. In this state, since the densityof the portions 3 b of the photoresist layer 3 to be removed isrelatively high and the density of the portions 3 c of the photoresistlayer 3 to be removed is relatively low, the amount of the developerreacting to the portions 3 b of the photoresist layer 3 to be removed issmaller than the amount of the developer reacting to the portions 3 c ofthe photoresist layer 3 to be removed. When development is performed inthis state, a result as illustrated in FIG. 6 may be obtained. Forexample, when the density of the portions 3 b of the photoresist layer 3to be removed is high, removal of the portions 3 b may not be complete.Accordingly, the width of the opening formed in the photoresist layer 3may decrease as the density of the openings increases.

In this state, when the contact holes are formed by patterning theto-be-patterned layer 2 under the photoresist layer 3, the widths ofcontact holes may be decreased or contact holes may not be properlyformed in a portion where the width of the opening formed in thephotoresist layer 3 is narrow. Consequently, in the formation of contactholes in the to-be-patterned layer 2, when the density of contact holesformed in a specific first area is higher than the density of contactholes to be formed in a second area, the width of each of the contactholes formed in the first area may be narrower than the width of each ofthe contact holes formed in the second area, or the contact holes maynot even be properly formed in the first area. Such inconsistency in thewidth of the contact holes may lead to defects later in manufacturedproducts.

Referring to FIG. 3 , as described above, in the display area DA, thefirst insulating layer 141 has the first contact holes CT1. In the firstscan drive circuit SDR1 to the third scan drive circuit SDR3 in theperipheral area PA, the first insulating layer 141 has the secondcontact holes CT2. In this state, in the second portion EP2 that is acurved edge of the display area DA, a gap between the first scan drivecircuit SDR1 to the third scan drive circuit SDR3 and the display areaDA may be relatively large. If the first insulating layer 141 were tonot have the dummy contact holes DCT in the second portion EP2, thedensity of the contact holes in an area around the second portion EP2would be lower than the density of the contact holes in other areas. Adifference in the density of the contact holes could cause a defect asdescribed above with reference to FIGS. 5 and 6 .

However, in the display apparatus according to the present embodiment,in an area around the second portion EP2 that is a curved edge of thedisplay area DA, the first insulating layer 141 may include the dummycontact holes DCT between the first scan drive circuit SDR1 to the thirdscan drive circuit SDR3 and the display area DA. Accordingly, when arereferred to as a plurality of contact holes, a rapid difference in thedensity of the contact holes, including the first contact holes CT1, thesecond contact holes CT2, and the dummy contact holes DCT altogether, inthe area around the second portion EP2 may be reduced. Accordingly, thedisplay apparatus according to the present embodiment may effectivelyprevent or reduce the likelihood of a defect in the formation of thecontact holes that may occur in the manufacturing process.

As illustrated in FIGS. 2 and 3 , a dummy scan drive circuit DSDR may belocated between the first scan drive circuit SDR1 and the second scandrive circuit SDR2, in the area around the second portion EP2 that is acurved edge of the display area DA. When the second portion EP2 has acurved shape as described above, the connecting wire CW2 connecting thefirst scan drive circuit SDR1 and the scan lines SL1, or the connectingwire CW2 connecting the second scan drive circuit SDR2 and the scanlines SL2, may not have a uniform extension direction. Accordingly, thelength of the connecting wire CW2 may increase. In these circumstances,to reduce the length of the connecting wire CW2, the first scan drivecircuit SDR1 electrically connected to the scan lines SL1 and the secondscan drive circuit SDR2 electrically connected to the scan lines SL2 maybe spaced apart from each other. The dummy scan drive circuit DSDR maybe located between the first scan drive circuit SDR1 and the second scandrive circuit SDR2, which are spaced part as described above.

As described above, the first insulating layer 141 of the first scandrive circuit SDR1 and the second scan drive circuit SDR2 include thesecond contact holes CT2, as illustrated in FIG. 3 . The second contactholes CT2 may be located at an approximately uniform density in thefirst insulating layer 141 in the first scan drive circuit SDR1 and thesecond scan drive circuit SDR2. In the case of the dummy scan drivecircuit DSDR, the first insulating layer 141 may include a plurality ofadditional dummy contact holes ADCT formed at a density that is the sameas or similar to that of the second contact holes CT2. Accordingly, thefirst insulating layer 141 may include a plurality of contact holes,including the second contact holes CT2 and the additional dummy contactholes ADCT altogether, at an approximately uniform density in the firstscan drive circuit SDR1, the dummy scan drive circuit DSDR, and thesecond scan drive circuit SDR2. In the display apparatus according tothe present embodiment, dummy contact holes may be located between thefirst scan drive circuit SDR1 and the dummy scan drive circuit DSDR orbetween the second scan drive circuit SDR2 and the dummy scan drivecircuit DSDR and the defective formation of contact holes that couldoccur in the manufacturing process may be effectively prevented orreduced. D.

The additional dummy contact holes ADCT in the first insulating layer141 in the dummy scan drive circuit DSDR may have a shape that is thesame as or similar to that of the dummy contact holes DCT illustrated inFIG. 4 .

In the case of the first contact holes CT1 of the display area DA, asillustrated in FIG. 4 , the source electrode 215 a or the drainelectrode 215 b may be connected to the first semiconductor layer 211thereunder. For example, the first contact holes CT1 of the display areaDA may be filled with a material that forms the source electrode 215 aor the drain electrode 215 b. The source electrode 215 a or the drainelectrode 215 b may be referred to collectively as a first wiring 151. Asurface of the first wiring 151 facing the substrate 100 may directlycontact a surface of the interlayer insulating layer 131 facing away thesubstrate 100.

In the case of the second contact holes CT2 of the peripheral area PA,as illustrated in FIG. 4 , the source electrode 225 a or the drainelectrode 225 b may be connected to the second semiconductor layer 221thereunder. The second contact holes CT2 of the peripheral area PA maybe filled with a material for forming the source electrode 225 a or thedrain electrode 225 b. The source electrode 225 a or the drain electrode225 b may be a second wiring. The first contact holes CT1 may be filledwith the first wiring 151, and the second contact holes CT2 may befilled with the second wiring 161.

In contrast, the dummy contact holes DCT in the peripheral area PA arenot filled with a wiring. Instead, the dummy contact holes DCT may befilled with an insulating layer such as a protection layer and/or theplanarization layer, 140 as illustrated in FIG. 4 . In the dummy scandrive circuit DSDR, the additional dummy contact holes ADCT in the firstinsulating layer 141 may be filled with an insulating layer such as theprotection layer and/or the planarization layer 140.

The source electrode 215 a or the drain electrode 215 b in the displayarea DA and the source electrode 225 a or the drain electrode 225 b inthe peripheral area PA may be simultaneously formed with the samematerial. Accordingly, in this case, each of the first wirings 151 maybe understood as having the same material as the second wirings 161.

As described above, the first scan drive circuit SDR1 to the third scandrive circuit SDR3 and the scan lines SL1, SL2, and SL3 may beelectrically connected to each other. To this end, the connecting wiresCW1 and CW2 may be provided between the first scan drive circuit SDR1 tothe third scan drive circuit SDR3 and the scan lines SL1, SL2, and SL3.Consequently, the connecting wires CW1 and CW2 may electrically connectthe first wiring, for example, the source electrode 225 a or the drainelectrode 225 b of the first scan drive circuit SDR1, to the third scandrive circuit SDR3, and the second wiring, for example, the sourceelectrode 215 a or the drain electrode 215 b, in the display area DA.Accordingly, each of the first wirings 151 may be electrically connectedto a corresponding one of the second wirings 161.

The connecting wires CW1 and CW2 may be located in a different layerfrom the scan lines SL1, SL2, and SL3, and may be connected to eachother via the contact holes formed in the insulating layer between theconnecting wires CW1 and CW2 and the scan lines SL1, SL2, and SL3. Insome implementations, the connecting wires CW1 and CW2 and the scanlines SL1, SL2, and SL3 may be simultaneously formed of the samematerial in the same layer. In this case, a bridge wires electricallyconnecting the connecting wires CW1 and CW2 and the scan lines SL1, SL2,and SL3 may be located in a different layer from the connecting wiresCW1 and CW2 and the scan lines SL1, SL2, and SL3. Each of the connectingwires CW1 and CW2 and any one of the scan lines SL1, SL2, and SL3corresponding thereto may be formed as one body. Consequently, each ofthe first wirings 151 may form one body with a corresponding one of thesecond wirings 161. In any case, it may be understood that the firstwirings 151 are electrically connected to conductive layers, and thesecond wirings 161 are electrically connected to conductive layers.

As described above, in the thin film transistor 210 located in thedisplay area DA, the first semiconductor layer 211 is located in thelower portion and the source electrode 215 a and the drain electrode 215b are located in the upper portion. The source electrode 215 a and thedrain electrode 215 b may contact the first semiconductor layer 211thereunder via the first contact holes CT1 formed in the firstinsulating layer 141 provided between the first semiconductor layer 211,and the source electrode 215 a and the drain electrode 215 b. When thethin film transistors 210 are located in the display area DA, the firstsemiconductor layers 211 are provided. The first semiconductor layers211 may be understood to be provided between the substrate 100 and thefirst insulating layer 141. At least a part of the upper surface of eachof the first semiconductor layers 211 facing the first insulating layer141 may be understood to be located at a lower end of the first contactholes CT1.

Likewise, in the thin film transistor 220 located in the peripheral areaPA, the second semiconductor layer 221 is located in the lower portionand the source electrode 225 a and the drain electrode 225 b are locatedin the upper portion. The source electrode 225 a and the drain electrode225 b may contact the second semiconductor layer 221 thereunder via thesecond contact holes CT2 formed in the first insulating layer 141provided between the second semiconductor layer 221, and the sourceelectrode 225 a and the drain electrode 225 b. When the thin filmtransistors 220 are located in the peripheral area PA, the secondsemiconductor layers 221 are provided. It may be understood that thesecond semiconductor layers 221 may be provided between the substrate100 and the first insulating layer 141. At least a part of the uppersurface of each of the second semiconductor layers 221 facing the firstinsulating layer 141 may be located at a lower end of the second contactholes CT2.

As illustrated in FIG. 4 , the display apparatus according to thepresent embodiment may include dummy semiconductor layers 201. It may beunderstood that the dummy semiconductor layers 201 are provided betweenthe substrate 100 and the first insulating layer 141, and at least apart of an upper surface of each of the dummy semiconductor layers 201facing the first insulating layer 141 is located at a lower end of thedummy contact holes DCT.

The first contact holes CT1, the second contact holes CT2, and the dummycontact holes DCT may be simultaneously formed by patterning the firstinsulating layer 141. In this state, when patterning the firstinsulating layer 141, that is, the gate insulating layer 121 and theinterlayer insulating layer 131, the buffer layer 110 and/or thesubstrate 100 under the first insulating layer 141 could be damaged, andthus it is desirable to prevent or minimize the generation of damage.The formation of the first contact holes CT1 and the second contactholes CT2 partially exposes the second semiconductor layers 221 locatedbetween the buffer layer 110 and the first insulating layer 141.Consequently, the second semiconductor layers 221 may protect the bufferlayer 110 and/or the substrate 100 thereunder.

When the dummy semiconductor layers 201 are located under the dummycontact holes DCT, the formation of the dummy contact holes DCTpartially exposes the dummy semiconductor layers 201 located between thebuffer layer 110 and the first insulating layer 141. Consequently, thedummy semiconductor layers 201 may protect the buffer layer 110 and/orthe substrate 100 thereunder. Although FIG. 4 illustrates that two dummycontact holes DCT correspond to one dummy semiconductor layer 201, insome implementations, the dummy contact holes DCT and the dummysemiconductor layers 201 may have a one-to-one correspondence andvarious modifications thereof are possible.

When the buffer layer 110 and/or the substrate 100 are formed of amaterial having excellent corrosion resistance, for example, when thesubstrate 100 is formed of a glass material, the dummy semiconductorlayers 201 may be omitted.

As described above, in the second portion EP2 that is a curved edge ofthe display area DA, a gap between the first scan drive circuit SDR1 orthe second scan drive circuit SDR2, which is located adjacent to thesecond portion EP2, and the second portion EP2, may be relatively large.For example, the gap may be relatively greater than the gap between thefirst portion EP1 that is a part of the first edge E1 that is a linearedge of the display area DA and the third scan drive circuit SDR3located adjacent to the first portion EP1. Since the second portion EP2has a curved shape, the connecting wires CW2 connecting the first scandrive circuit SDR1 and the scan lines SL1 or the connecting wires CW2connecting the second scan drive circuit SDR2 and the scan lines SL2 mayhave not a uniform extension direction. Accordingly, the length of theconnecting wire CW2 is greater.

In addition, the greatest distance between the closest ones of theconnecting wires CW2 passing between the dummy contact holes DCT isgreater than the largest distance between the closest ones of theconnecting wires CW1 adjacent to the first portion EP1. This is because,since the connecting wires CW2 connecting the first scan drive circuitSDR1 and the scan lines SL1 or the connecting wires CW2 connecting thesecond scan drive circuit SDR2 and the scan lines SL2 have no uniformextension directions and have inclined extension directions with respectto each other, the largest distance between the closest ones of theconnecting wires CW2 is increased accordingly. The largest distancebetween the closest ones of the connecting wires CW2 may be, forexample, a distance between the closest ones of the connecting wires CW2in the second portion EP2 of FIG. 3 . For reference, although FIG. 3illustrates that the distance between the connecting wires CW1 is alwaysconstant, the present invention is not limited thereto.

FIG. 7 illustrates a cross-sectional view schematically depicting aportion of a display apparatus according to another embodiment. FIG. 7illustrates an enlarged view of an area around the dummy contact holesDCT located in the peripheral area PA. A conductive material layer 203may be located in the dummy contact holes DCT. An end portion of theconductive material layer 203 facing the second insulating layer, forexample, the planarization layer 140 located above the conductivematerial layer 203 and the first insulating layer 141, may be locatedinside the dummy contact holes DCT. The conductive material layer 203inside the dummy contact holes DCT may not be electrically connected toanother external conductive layer.

In the manufacturing process, after the first contact holes CT1, thesecond contact holes CT2, and the dummy contact holes DCT are formed inthe first insulating layer 141, a conductive layer may be formed tocover the first insulating layer 141. The conductive layer may bepatterned to fill the first contact holes CT1 and the second contactholes CT2, and the source electrodes 225 a and the drain electrodes 225b located on the first insulating layer 141 may be formed. In thisstate, the portion of the conductive layer filling the dummy contactholes DCT may be entirely removed in a pattering process. As illustratedin FIG. 7 , when the dummy contact holes DCT are deep, the conductivelayer may not be completely removed and may remain in the dummy contactholes DCT.

In some embodiments, the substrate 100 may include the display area DAand the peripheral area PA outside the display area DA. The firstinsulating layer 141 may be located on the substrate 100 in the displayarea DA and the peripheral area PA. The first insulating layer 141 mayinclude the first contact holes CT1 located in the display area DA, thesecond contact holes CT2 located in the peripheral area PA, and thedummy contact holes DCT located between the first contact holes CT1 andthe second contact holes CT2. The connecting wires CW2 may electricallyconnect a material filling each of the first contact holes CT1 and amaterial filling a corresponding one of the second contact holes CT2 andmay between the dummy contact holes DCT.

By way of summation and review, when some of the pixels located in adisplay area are defective, the quality of an image realized by thedisplay apparatus may deteriorate. Accordingly, it is desirable toprevent the generation of a defective pixel in the manufacturing processor to reduce a defective pixel generation rate.

In a general manufacturing process, defective pixels may be generated atan edge of the display device.

Embodiments provide a display apparatus that allows for a generation ofdefects in pixels at an edge of a display area in a manufacturingprocess to be reduced.

Example embodiments have been disclosed herein, and although specificterms are employed, they are used and are to be interpreted in a genericand descriptive sense only and not for purpose of limitation. In someinstances, as would be apparent to one of ordinary skill in the art asof the filing of the present application, features, characteristics,and/or elements described in connection with a particular embodiment maybe used singly or in combination with features, characteristics, and/orelements described in connection with other embodiments unless otherwisespecifically indicated. Accordingly, it will be understood by those ofskill in the art that various changes in form and details may be madewithout departing from the spirit and scope thereof as set forth in thefollowing claims.

What is claimed is:
 1. A display apparatus, comprising: a substrateincluding a display area and a peripheral area outside the display area;a first drive circuit located in the peripheral area, the first drivecircuit to generate a scan signal and apply the scan signal to a thinfilm transistor that is located in the display area and is electricallyconnected to a pixel electrode; a first insulating layer over thesubstrate in the display area and the peripheral area, the firstinsulating layer including a plurality of first contact holes located inthe display area and a plurality of first dummy contact holes in theperipheral area such that the plurality of first dummy contact holes arelocated between the plurality of first contact holes and the first drivecircuit; and a second insulating layer disposed over the firstinsulating layer and filling the plurality of first dummy contact holes.2. The display apparatus as claimed in claim 1, further comprising:first wirings filling the plurality of first contact holes; and firstconnecting wirings connecting the first wirings to the first drivecircuit, the first connecting wirings passing between the plurality offirst dummy contact holes.
 3. The display apparatus as claimed in claim1, further comprising a second drive circuit located in the peripheralarea, wherein the first insulating layer further includes a plurality ofsecond contact holes in the display area and a plurality of second dummycontact holes in the peripheral area such that the plurality of seconddummy contact holes area located between the plurality of second contactholes and the second drive circuit, and the second insulating layerfills the plurality of second dummy contact holes.
 4. The displayapparatus as claimed in claim 3, further comprising: first wiringsfilling the plurality of first contact holes; second wirings filling theplurality of second contact holes; first connecting wirings connectingthe first wirings to the first drive circuit, the connecting wiringspassing between the plurality of first dummy contact holes; and secondconnecting wirings connecting the second wirings to the second drivecircuit, the second connecting wirings passing between the plurality ofsecond dummy contact holes.
 5. The display apparatus as claimed in claim4, wherein the first insulating layer further includes a plurality ofthird dummy contact holes between the plurality of first dummy contactholes and the plurality of second dummy contact holes.
 6. The displayapparatus as claimed in claim 5, wherein the second insulating layerfills the plurality of third dummy contact holes.
 7. The displayapparatus as claimed in claim 3, wherein the first insulating layerfurther includes a plurality of additional dummy contact holes betweenthe first drive circuit and the second drive circuit.
 8. The displayapparatus as claimed in claim 7, wherein the second insulating layerfills the plurality of additional dummy contact holes.
 9. The displayapparatus as claimed in claim 3, further comprising a dummy drivecircuit located in the peripheral area and between the first drivecircuit and the second drive circuit.
 10. The display apparatus asclaimed in claim 9, wherein the first insulating layer further includesa plurality of third dummy contact holes between the plurality of firstdummy contact holes and the plurality of second dummy contact holes andbetween the dummy drive circuit and the display area.
 11. The displayapparatus as claimed in claim 10, wherein the second insulating layerfills the plurality of third dummy contact holes.
 12. The displayapparatus as claimed in claim 1, further comprising a plurality of firstsemiconductor layers between the substrate and the first insulatinglayer, wherein at least a part of an upper surface of each of theplurality of first semiconductor layers that faces the first insulatinglayer is located at a lower end the plurality of first contact holes.13. The display apparatus as claimed in claim 12, further comprising aplurality of dummy semiconductor layers between the substrate and thefirst insulating layer, wherein at least a part of an upper surface ofeach of the plurality of dummy semiconductor layers, the upper surfacefacing the first insulating layer, is located at a lower end of theplurality of first dummy contact holes.
 14. The display apparatus asclaimed in claim 1, wherein at least a portion of an edge of the displayarea has a round shape, and the plurality of first dummy contact holesare located adjacent to the portion of the edge of the display areahaving the round shape.
 15. The display apparatus as claimed in claim 1,further comprising a conductive material layer located in the pluralityof first dummy contact holes, an end portion of the conductive materiallayer facing the second insulating layer being located in the pluralityof first dummy contact holes.
 16. The display apparatus as claimed inclaim 1, wherein the second insulating layer completely fills theplurality of first dummy contact holes.
 17. The display apparatus asclaimed in claim 1, wherein the second insulating layer directlycontacts a bottom surface of at least one first dummy contact holes.